Blasting paper sheet



G. S. CLARK- v BLASTING PAPER SHEET. APPLICATION FILED APR. 9;1920.

376,676. Patentd May 3, 1921.

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A TTORNE Y.

UNITED STATES PATENT OFFICE.

GEORGE S. CLARK, OF BLACKEY, KENTUCKY.

IBL-ASTING IAPER SHEET.

Application filed April 9,

T0 aZZ whom may concern.

Be it known that I, Gnonon S. CLARK, a citizen of the United States, residing at Blackey, in the county of Letcher and State of Kentucky, have invented certain new and useful Improvements in Blasting Paper Sheets; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to blasting paper sheet and it consists in the novel features hereinafter described and claimed.

It is a well established fact among those engaged in the coal mining industry that no two seams of coal have the same structure and that it requires several experimental shots with various sized cartridges and different amounts of powder to ascertain the best charge for the particular coal to be worked. Once the right size cartridge is found a pin or mandrel of correct diameter must be kept always at hand and upon which the paper is wound orrolled to obtain the right size shell when the cartridge is to be made.

Notwithstanding this the shell is liable to bag causing windy shots which not only tear down very little coal but are deleterious to all nearby props and brattices, very dangerous in igniting coal dust causing the most destructive of mine explosions.

If the shell is to be used in a wet hole, soap or other greasy substance must be used at the seam to affect waterproofing which is not only expensive and troublesome, but unsatisfactory as well as the soap will frequently melt and loosen when coming in contact with water, ruining the cartridge, causing hung shots, involving much extra labor in reboring or boring out the hole and makin a new cartridge. In addition to this the making of a shell requires a certain amount of skill and a deft hand that inexperienced miners do not possess.

It is the object of the present invention to provide a blasting paper sheet of a size corresponding with that which is recognized as being the approved standard and the improved sheet'is provided at one side and along one edge thereof with linear graduations or a scale and at the same side and adjacent the said scale with spaced lines indicating the diameter of the shell when the Specification of Letters Patent.

Patented May 3, 1921.

1920. Serial No. 372,533.

sheet is rolled in cylindrical form preparatory to receiving the powder or charge.

Thus it will be apparent that a shell may be formed of any desired diameter and accurately judged inasmuch as the, edge of the sheet is brought into register of one of the lines which indicate the diameter and is secured to the intermediate portion of the sheet and when a shell of particular length is desired it may be cut off at any point along the graduations which indicate the length. The sheet is provided upon its obverse side and along that edge portion whereat the linear scale is printed with a gummed surface or an adhesive which when damped is employed for connecting the free edge portion with the intermediate portion thereof in the formation of the shell body or cylinder.

In the accompanying drawing 2- Figure 1 is a plan view of the obverse side of the blasting paper sheet.

Fig. 2 is a similar view of the reverse side thereof.

The blasting paper sheet comprises a blank 1 preferably rectangular in form and of approved standard dimensions. The sheet 1 is provided upon its obverse side and along one longitudinal edge portion with a linear scale 2. The graduations of the said scale are preferably in inches and fractions thereof. The sheet is further provided upon its obverse side with lines 3 which extend the full length thereof, which are parallel with the length of the scale 2 and which are spaced from each other at predetermined distances to produce shells varying in di ameter as for instance 1 inch, inches, 2 inches, 2} inches and so on. In the formation of a shell of any particular diameter it is apparent that this may be accomplished by rolling the sheet 1 so that the edge at which the scale 2 is located is brought into register with any one of the lines 3. The edge portion of the sheet at which the graduations are located is thensecured to the intermediate portion by Inoistening the gum or adhesive 4:. Thus a shell of desired diameter is formed. It is also apparent that when it is desired to make the'shell of any particular length it may be torn off or cut off at one of the graduations upon the scale 2. This shell will hold a certain amount of powder, and by experiment previously conducted this amount of powder will be required for the advantageous use in blasting out a particular seam of coal.

Having described the invention claimed is:

A blasting paper sheet comprising a blank having lines upon its side and a-scale arranged along one edge portion of the sheet, the lines being provided with numerals or characters which indicate the diameter of a cylinder when the sheet is rolled and the edge of the sheet .at which the graduations are located is secured to the intermediate what is portion of the sheet at the line, the lines being spaced from that edge of the sheet at which the scale is located at distances 15 equal respectively to the diameters indicated by said numerals multiplied by 3.1416.

In testimony whereof I afiix my signature in presence of two witnesses.

GEORGE s. oLAriK.

Witnesses:

HENRY A. SPALDING, L. J. WREDHAM. 

